1. Field of the Invention
The present invention relates to solid-state storage devices. More specifically, the present invention relates to systems and methods for measuring and monitoring the useful life of solid-state storage devices in operating environments.
2. Description of the Related Art
Rotating hard disk drives (HDD) used, for example, in desktop, laptop, notebook, sub-notebook, tablet and embedded computers support an industry-standard advanced technology attachment (ATA) command called Self Monitoring and Reporting Technology (SMART). The SMART function was designed to act as an “early warning system” for pending problems with mechanical media such as HDDs. The integrated controller on the HDD works in conjunction with various sensors to monitor a variety of different parameters within the HDD, such as mechanical wear of the HDD's spindle motor, to determine if any of the parameters are drifting from a norm that would indicate a possible problem with the HDD.
By contrast with HDDs, solid-state storage subsystems generally do not have moving parts. Thus, many of the parameters monitored by the SMART function used in HDDs are not applicable to solid-state storage subsystems. Solid-state storage subsystems generally include non-volatile storage components that can lose the ability to retain data stored thereon after approximately hundreds of thousands to approximately millions of write/erase cycles.
Generally, non-volatile storage components used in solid-state storage subsystems have a finite number of program/erase cycles (usually specified by component vendors as “endurance”) that are recommended or guaranteed for proper data storage and retrieval. The number of such cycles varies by orders of magnitude based on the type of storage component used. Unfortunately, however, there is currently no method that can reliably determine or predict when the recommended or guaranteed endurance in a particular non-volatile storage component will be exceeded. Thus, solid-state storage subsystems are often allowed to operate beyond the specified endurance until a failure occurs, causing unscheduled system down time and potentially significant data loss.